Prepayment coin box system



y 11, 19 H. M. BAS'COM 2,319, 32

PREPAYMENT COIN BOX SYSTEM Filed April 9,1940

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FIG

INVENTOR H. M BA SCOM Bragg? n l ATTORNEY Patented May 11, 1943 UNITED STATES PATENT OFFICE PREPAYMENT COIN BOX SYSTEM Henry M. Bascom, Brooklyn, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application April 9, 1940, Serial No. 328,611

6 Claims.

a device at a station, and held in suspense therein,to initiate a call, which coin is later collected or refunded depending on whether the desired connection is completed or not, said coin collection or return being accomplished by a polarized electromagnet controlled from the central office by means of a relatively high voltage direct current transmitted over the line in either of two directions, in practice of the general order of 110 volts.

Systems of the above character usually employ an auxiliary coin battery at the exchange which is separate and distinct from the regular, low voltage central office battery and in small exchanges where only a small number of coin box lines are in service, the expense of maintaining such an auxiliary current supply may be unduly high.

An object of the present invention, therefore, is to provide means whereby the regular low voltage central ofiice battery may also serve to supply the higher potential current for controlling the collection or return of coins at coin box stations.

A feature of the invention whereby the foregoing object is obtained resides in employing a plurality of high capacitance condensers, for example, of the electrolytic type, which are normally connected in parallel across the central office battery and charged thereby and in a switching arrangement whereby these condensers may be connected in series-aiding to the line at the time of coin disposal.

The invention will be understood from the following description and accompanying drawing which shows in Fig. 1 a coin subscribers line and a portion of an operators cord circuit, arranged in accordance with the present invention, adapted to be connected thereto and to control the disposition of coins thereover. Fig. 2 shows a modi fication of a portion of Fig. 1.

Referring to the drawing, Fig. 1 represents a subscribers line L extending from a coin ,sub-' scribers station A to, and terminating in, a jack at the central office together with a portion of the answering end of an operators link circuit C adapted to be connected to said line and having associated therewith a source of high voltage coin potential in accordance with the present inven-' tion which source comprises a single group of three condensers having a relatively large current storing capacity, as for example the type known as electrolytic condenser, which condensers are normally connected in multiple to the central office battery and charged thereby. In addition to the condensers the necessary switches are shown for disconnecting said condensers from the battery and selectively applying them in series-aiding in either polar direction between one conductor of the line and ground over which circuit the connected condensers may discharge to actuate an electromagnet associated with the coin box mechanism at the subscribers station, and Fig. 2 represents an alternative coin potential source comprising two', similar groups, of three condensers ea'ch,'both' of which groups have their individual units connected in multiple to the central oflice battery, together with switching apparatus for disconnecting either group from the battery and connecting the respective elements thereof in' series-aiding in a predetermined polar direction between one side of the line and ground. V A description of the operation of the circuit arrangement of the present invention follows: It will first be assumed that the subscriber' at station A has deposited a coin l'in the usual manner thereby attracting the attention of the operator at the central offi'ce who at the request of the subscriber has established a desired connection with the line of another subscriber, not shown, and at some later stage of the connection desires either to collect the coin or return it to the calling subscriber, which operations are efiected, as well understood, by the application of a relatively high potential direct current impulse to the line.

In case the coin is to be collected, a positive polarity impulse is applied to the line and if the coin is to be returned to the'subscriber a negative polarity impulse is applied. In the present invention (Fig. 1), thesource of the foregoing coin control potential resides in condensers C1, C2 and C3, which are normally charged in parallel from the grounded central office battery CB in an obvious circuit, which include normal contacts of relay 2. S

If we assume that the operator desires to collect the coin I at station A she will operate the collect key CK of her link circuit C thereby completing the following circuit, ground, contacts 3 ofCK, conductor 4 ,contact 5 of relayfi and windf ing o f relay l to battery.' Relay 'l'operates ther by completing, at its contacts B a]jc ir,cuit to opera ate relayZ overits lower winding, Relay? in operating opens its contacts 9-l4, an d close's contacts l5'l8 thereby disconnecting condensers, C1, C2 and C from battery CB, operatingrelaylq over contact I! of relay 2, and connectingcong densers C1, C2 and C3 in series-aiding, between ground and the tip conductor of the line in a positive direction in the following circuit, ground, contacts. 2!] of relay], contacts Zl of relay 6, contac, ts 22 of relay l9, contacts E5 of relay 2, negatively charged plate of condenser 03, positively charged plate of condenser C contact 23 of relay l 9,negatively charged plate of condenser C2, positively charged plate of condenser 02, contact 24 of relay I9, negative plateoi condenser C1, positive plate of condenser Ci, contact I8 of relay 2, con-" tact 25 of relay l9, contact 26 of relay 1, current limiting resistance lamp 21, and contacts 28 of key GK and the tip of the line L to ground through the winding of magnet 29 at station A to cause its operation, "Idue toithe discharge of the condensers in the circuit,'in such a manner as to cause the coin I to be deposited in the cash box.

When relay l9 operated it closed at its contacts 29 a locking circuit for relay 2 including its upper winding. Release of key CK releases relays 1 and I9 followed by the releaseof'relay'i; thereby reconnecting condenser Ci'C3;in.multiple across the battery CB.

In case the coin is to be retnrnedzinsteadbf collected the key RK is operated, thereby. immediately operating relay 6, instead of 1, followedby theroperatiomof relays :2--.and l9thereby disconnecting; the; condensers fromtheubattery, asbefore,- but now .due: to theoperated condition of relay: 6,; and the releasedcondition of relay 1, the connection of thezcondensenwith respect to the 'lineis reversed so that the negative plate of con- .denserCz. is connected: to the line: and the positive plate ofwcondenserCr is grounded.

.-.I-n'central offices where the. frequencyof calls from coinrbox stations, and the consequent .demand for 1 coin control ;.potentials, .exceeds the ability of--a' single :group of condensers to' satisfy these requirements, two groups of condensers as shown in Fig.2 may beemployed, onegroup being usedfor coincollection only, -and theother group for-coin return: only. In suchan event the four conductors ofaFig. 2, shown terminatingin the broken lines a:a'.are connectedto the'four conductorsleadingto the link: circuit C in' place of the (four conductors extending from the'previously :described; potential source of Fig. 1.

- In thearrangementof Fig.2; condensers Cl-C6 are normally connected in. multiple with the central ofiicebattery-CB overcontacts of relays '30 and-3| Operation of the collect! key CK grounds conductor 4 at contacts 3 of. the key thereby operating relay 30 over its lower winding, which relay in operating .extends its operating ground to relay 32 which thereupon operates.

.Relay.3ll disconnects condensers C1, C2 and C3 fromtbattery CB .anda circuit is now completed fromground, contacts.33 of relay 32, contacts 34 of. relay 30,- tothe negativeplate of condenser C3.

The .positive plate ofcondenser C3 is connected to the negative plate of: condenser C2. overcontacts 35.01" relay 32, the..positive plate of condenser C2 is connected over .contacts 36 of relay .32 -to the negative-plate of condenser C1, 1 and the positive plate of.Ci is connected-oven contacts 31 of relay 3llrcontacts' 3B:of r'elays32, conductor. 39, and'contacts'28;of.keyiGK to. the tipotthe line L. ,Condensers. C1. tolcs being, connected.in series-aiding with the.positivelycharged.plate.of.C1totheline, the discharge impulse which follows-will be. in. a positive direction.thereby .causing thecoin I to 'becollected. When relay.32 operates -itralso completesa locking circuit f or. relay 30-which includes its upper winding.

'Operationtof -key .RK .causes the successive operationot relaysl3l. and 40. to cause condensers C4.Csto be disconnected fromfibattery CB and connected.inseries-aiding with the negative plate oficondenser C4 connected to the line andthe positive. Plate of Ce connected to ground.

Whatis claimed is:

1. 'In a common battery telephone system, an exchange, a calling line having a coin device associated therewith, a link. circuit at said ex- .switching means associated with said link circuit adapted when operated to disconnect said condensers from said battery and to connect them in series-aiding relation to said line to actuate. said coin device.

2. In a common battery telephone system, an exchange, a calling line having a coin disposal device associatedtherewith and adapted to be controlled thereover, a link circuit at said exchange adapted to be connected to said line, an exchange battery forsupplyingtalking and signaling current to. said ,line and-link .circuit, --a plurality of condensers divided: into two groups and normally connected in parallel withieach other and said battery, and selective switching means associated'with saidxlink for connecting either group to saidline-in series-aidingrelation, to the exclusion of: said battery,'the connection of each group to the line being efiected in such'a manner that said-groups will discharge into; said line in opposite directions.

3. In a telephone system, an exchange, a-calling line having a coin device associated therewith, said device being adapted to receive a'coin and hold it in suspense therein and to dispose of said coin in eitherof two difierent manners responsive to a unidirectional current impulse, in a'particular polar direction, over:said line,:a link circuit at said exchange adapted to-be connected to said line, an exchange battery, azplurality of condensers normally connected in'multiple with said battery and charged thereby; and selective switching means associated with:said link-circuit adapted when operated to "disconnectisaid condenser from-said battery andconnect them in-series-aidingrelation to said line in either polar'direction.

-4. In a telephone exchange system comprising a paystation equipped with an electrically actuated coin disposal device, means for operating said device comprising a source 'of direct current whose voltage is less than that required to actuate said device, a; plurality of condensers normally connected to "said source and charged thereby, and means for disconnecting said condensers from said source and Jfor connecting them in series-aiding relation to said device.

5. In a paystation telephone'exchange system. employing electrically actuated coin disposal devices at the stations, means'for actuating said devices comprising a plurality of condensers each of which isnorrnally maintained charged to' a predetermined potential less than' the voltage required to' operate said devices, and switching means for selectively connecting said charged condensers in.series-aidingrelation to a desired on -of said devices.

6. The combination in a telephone system having a'central battery of a given potential, of lines each connected at its distant end to a coin disposal device responsive only to a potential higher than thatof said battery, with means for operating said coin disposal devices by transient currents derived from said battery by condensers and a switching arrangementfor charging said condensers in parallel from said battery and dis-' charging said condensers inseries into saidlines.

HENRY M. BASCOM. 

